The speakerphone device has been in use for years on traditional telephone lines around the world. This type of device generally is an instrument utilizing a switching technology that allows one or the other party to speak at once, but not simultaneously. There are more advanced devices that integrate DSP's (Digital Signal Processors) to accomplish a Full-Duplex (simultaneous conversation), but they are very expensive by comparison. See for example U.S. Pat. No. 5,657,384, Staudacher et al., which discloses a Full Duplex Speakerphone using DSP technology.
The invention presented in this disclosure is an inexpensive Full-Duplex solution for the new and exciting Internet using standard analog techniques. Numerous companies are offering free long-distance phone calls over the Internet, but users are mostly restricted to using headphones, due to echo. DSP technology is prohibitive, due to the long delay before the echo occurs. This long delay would require a rather large amount of memory and CPU overhead resulting in too expensive of a device for the consumer market.
The invention presented in this disclosure accomplishes a Full-Duplex conversation, without echo, over the Internet at a very inexpensive price. The invention makes an Internet conversion duplicate the natural sound of a face-to-face conversion.